1. Field of the Invention
This invention relates to an ophthalmologic apparatus such as an autorefractometer used for the measurement of an eye to be examined in a hospital or an optician""s store.
2. Related Background Art
There are known an ophthalmologic apparatus for effecting auto-alignment after manual alignment, and an ophthalmologic apparatus which can select manual alignment and auto-alignment. However, in the ophthalmologic apparatus for effecting auto-alignment after manual alignment, when alignment becomes impossible due to some cause or other after auto-alignment has been started, alignment must be manually effected again from the first. Also, after auto-alignment has been started, if alignment is manually effected without noticing it, measurement will sometimes become impossible. Also, in an ophthalmologic apparatus capable of effecting both manual alignment and auto-alignment, the changeover between the manual operation and the automatic operation is cumbersome, and an improvement in operability is required.
The present invention aims at improvements in the ophthalmologic apparatuses according to the prior art and a primary object thereof is to provide an ophthalmologic apparatus excellent in operability. Another object of the present invention is to provide an ophthalmologic apparatus in which a smooth shift is possible between manual alignment and auto-alignment. Still another object of the present invention is to provide an ophthalmologic apparatus that quickly and reliably makes alignment and measurement possible. Yet still another object of the present invention is to provide an ophthalmologic apparatus provided with an optical element with a prism that makes alignment possible by a simple construction.
The ophthalmologic apparatus according to the present invention for achieving the above objects is an ophthalmologic apparatus comprising a measuring optical system that optically measures an eye to be examined, a detection system that detects alignment information of the eye for the measurement, a driving mechanism that moves the measuring optical system relative to the eye, an operating device that allows an operator to manually control the driving mechanism in order to move the measuring optical system, and a controller that controls the driving mechanism to perform alignment of the measuring optical system with respect to the eye, with a plurality of modes including a first mode executing alignment within a predetermined range based on the alignment information of the detection system and a second mode executing manual alignment within a range broader than the predetermined range based on the operation of the operation device, wherein the controller automatically changes between the first mode and the second mode based on a predetermined event.
Further objects and forms of the present invention will become apparent from the following description of some embodiments of the invention.